The main feature of a Sharigan user is it's abilty to copy Ninjistu, Genjistu and Taijistu just by seeing the technique only once. Hatake Kakashi has mastered this and has discovered what the Sharigan eye was really used for.
First comes the Form manipulation which is where the Sharigan user uses the eye of insight to copy the opponents movements. Secondly is the Technique manipulation which the Sharigan user uses the insight and the copy wheel copy technique to copy an opponents justu which combines with the Form manipulation to freak out the opponent. Finaly using the copy wheel hyponosis technique the Sharigan user hypnotises the oppoent and suggests things that they are going say which means they can copy, this is combine with a genjistu technique and the other manipulations to give the Sharigan user the illusion of seeing into the future, this is best seen during the first fight against Zabuza
Sakura: if sasuke has the same bloodline lmiit as kakakshi sesei then this fight is going to be over